1. Field of the Invention
The present invention relates to a method of manufacturing an ophthalmic lens for making an optical display by means of an optical imager designed to allow information of the image or multimedia type to be viewed. The term “lens” is used herein to designate an optical system suitable in particular for being positioned in a frame for spectacles or eyeglasses.
This term “lens” is used to mean a finished lens ready for placing on a spectacles frame, or an unfinished lens or lens blank, i.e. that still needs to be subjected to at least one treatment, e.g. surfacing, in order to be usable.
2. Description of Related Art
The document WO 2006/016086 discloses a method of manufacturing a vision-correction lens 1 as represented in FIG. 1, that has a front face 1A and a rear face 1B, and into which light beams coming from a micro display 5 and emitted by an optical element of a light beam generator system 2 are introduced via an entry surface 3 and directed towards the eye of the wearer to enable information content to be viewed. The light beams are reflected a plurality of times between two reflection faces, between being introduced into the lens and exiting therefrom, these two reflection faces being faces of a transparent optical insert constituted by a light guide 4. According to this known method, the insert 4 is completely contained within the lens 1.
With this method of manufacturing an ophthalmic display, the vision of a user can be corrected, while being mass-produced in reliable manner, with this being achieved by decoupling the display and the vision-correction functions.
The entry surface 3 is formed by making a molded cavity in the lens, and it constitutes the bottom of the cavity. The cavity is molded by means of a stud secured to a mold portion, and the insert 4 is temporarily secured to this stud prior to molding. Once the lens is manufactured, the light beam generator system 2 is then placed on this entry surface 3.
Other solutions propose such lens for making an optical display with complex light beam generator system formed by two optical pieces as represented in FIG. 2.
The first beam generator piece 2A is placed and stuck on the rear face of the light guide 4 and the second optical piece 2B is placed and stuck on the front face of the light guide 4. Such arrangement results in a beam generator system having a smaller volume and a repartition around the lens.